linux.git/include/linux/blk-mq.h, branch v5.0-rc2

block: make request_to_qc_t public

2018-12-18T16:50:47+00:00

block consumers will need it for polling requests that
are sent with blk_execute_rq_nowait. Also, get rid of
blk_tag_to_qc_t and open-code it instead.

Reviewed-by: Jens Axboe 
Signed-off-by: Sagi Grimberg 
Signed-off-by: Christoph Hellwig

blk-mq: change blk_mq_queue_busy() to blk_mq_queue_inflight()

2018-12-18T04:31:42+00:00

There's a single user of this function, dm, and dm just wants
to check if IO is inflight, not that it's just allocated.

This fixes a hang with srp/002 in blktests with dm, where it tries
to suspend but waits for inflight IO to finish first. As it checks
for just allocated requests, this fails.

Tested-by: Mike Snitzer 
Signed-off-by: Jens Axboe

block: move queues types to the block layer

2018-12-04T18:38:17+00:00

Having another indirect all in the fast path doesn't really help
in our post-spectre world.  Also having too many queue type is just
going to create confusion, so I'd rather manage them centrally.

Note that the queue type naming and ordering changes a bit - the
first index now is the default queue for everything not explicitly
marked, the optional ones are read and poll queues.

Reviewed-by: Sagi Grimberg 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

blk-mq: add mq_ops->commit_rqs()

2018-11-29T17:11:56+00:00

blk-mq passes information to the hardware about any given request being
the last that we will issue in this sequence. The point is that hardware
can defer costly doorbell type writes to the last request. But if we run
into errors issuing a sequence of requests, we may never send the request
with bd->last == true set. For that case, we need a hook that tells the
hardware that nothing else is coming right now.

For failures returned by the drivers ->queue_rq() hook, the driver is
responsible for flushing pending requests, if it uses bd->last to
optimize that part. This works like before, no changes there.

Reviewed-by: Omar Sandoval 
Reviewed-by: Ming Lei 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

blk-mq: Simplify request completion state

2018-11-26T17:34:27+00:00

There are no more users relying on blk-mq request states to prevent
double completions, so replace the relatively expensive cmpxchg operation
with WRITE_ONCE.

Reviewed-by: Christoph Hellwig 
Signed-off-by: Keith Busch 
Signed-off-by: Jens Axboe

blk-mq: Return true if request was completed

2018-11-26T17:34:24+00:00

A driver may have internal state to cleanup if we're pretending a request
didn't complete. Return 'false' if the command wasn't actually completed
due to the timeout error injection, and true otherwise.

Reviewed-by: Christoph Hellwig 
Signed-off-by: Keith Busch 
Signed-off-by: Jens Axboe

blk-mq: remove 'tag' parameter from mq_ops->poll()

2018-11-26T15:25:44+00:00

We always pass in -1 now and none of the callers use the tag value,
remove the parameter.

Reviewed-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

blk-mq: provide a helper to check if a queue is busy

2018-11-08T17:24:23+00:00

Returns true if the queue currently has requests pending,
false if not.

DM can use this to replace the atomic_inc/dec they do per device
to see if a device is busy.

Reviewed-by: Mike Snitzer 
Reviewed-by: Bart Van Assche 
Signed-off-by: Jens Axboe

blk-mq-tag: change busy_iter_fn to return whether to continue or not

2018-11-08T17:24:07+00:00

We have this functionality in sbitmap, but we don't export it in
blk-mq for users of the tags busy iteration. This can be useful
for stopping the iteration, if the caller doesn't need to find
more requests.

Reviewed-by: Mike Snitzer 
Signed-off-by: Jens Axboe

nvme: add separate poll queue map

2018-11-07T20:45:00+00:00

Adds support for defining a variable number of poll queues, currently
configurable with the 'poll_queues' module parameter. Defaults to
a single poll queue.

And now we finally have poll support without triggering interrupts!

Reviewed-by: Hannes Reinecke 
Reviewed-by: Keith Busch 
Signed-off-by: Jens Axboe